Programmed Co-delivery of tamoxifen and docetaxel using lipid-coated mesoporous silica nanoparticles for overcoming CYP3A4-mediated resistance in triple-negative breast cancer treatment.

PURPOSE: This study aims to revolutionize the treatment of aggressive triple-negative breast cancer (TNBC), notorious for its resistance to standard therapies. By ingeniously combining Tamoxifen (TMX) and Docetaxel (DTX) within a lipid-coated mesoporous silica nanoparticle (LP-MSN) delivery system, we intend to enhance therapeutic efficacy while circumventing DTX resistance mediated by CYP3A4 expression. METHODS: We rigorously tested TNBC cell lines to confirm the responsiveness to Docetaxel (DTX) and Tamoxifen (TMX). We adeptly engineered LP-MSN nanoparticles and conducted a thorough examination of the optimal drug release strategy, evaluating the LP-MSN system's ability to mitigate the impact of CYP3A4 on DTX. Additionally, we comprehensively analyzed its pharmacological performance. RESULTS: Our innovative approach utilizing TMX and DTX within LP-MSN showcased remarkable efficacy. Sequential drug release from the lipid layer and mesoporous core curbed CYP3A4-mediated metabolism, substantially enhancing cytotoxic effects on TNBC cells without harming normal cells. CONCLUSION: This pioneering research introduces a breakthrough strategy for tackling TNBC. By capitalizing on synergistic TMX and DTX effects via LP-MSN, we surmount drug resistance mediated by CYP3A4. This advancement holds immense potential for transforming TNBC treatment, warranting further clinical validation.

Recent Advances in Mesoporous Silica Nanoparticles Delivering siRNA for Cancer Treatment.

Silencing genes using small interfering (si) RNA is a promising strategy for treating cancer. However, the curative effect of siRNA is severely constrained by low serum stability and cell membrane permeability. Therefore, improving the delivery efficiency of siRNA for cancer treatment is a research hotspot. Recently, mesoporous silica nanoparticles (MSNs) have emerged as bright delivery vehicles for nucleic acid drugs. A comprehensive understanding of the design of MSN-based vectors is crucial for the application of siRNA in cancer therapy. We discuss several surface-functionalized MSNs' advancements as effective siRNA delivery vehicles in this paper. The advantages of using MSNs for siRNA loading regarding considerations of different shapes, various options for surface functionalization, and customizable pore sizes are highlighted. We discuss the recent investigations into strategies that efficiently improve cellular uptake, facilitate endosomal escape, and promote cargo dissociation from the MSNs for enhanced intracellular siRNA delivery. Also, particular attention was paid to the exciting progress made by combining RNAi with other therapies to improve cancer therapeutic outcomes.

Long term intake of 0.1% ethanol decreases serum adiponectin by suppressing PPARγ expression via p38 MAPK pathway.

Light alcohol consumption was reported to be negatively associated with insulin resistance and risk of cardiovascular diseases; however, the results were inconsistent. We here investigate whether long term intake of low-concentration ethanol can affect adiponectin levels. Male Wistar rats were exposed to 0.1% ethanol in drinking water for 26weeks. Visceral adipose tissue (VAT) was cultured and treated with ethanol, SB203580, GW9662, or rosiglitazone. Adiponectin in serum and culture supernatant were measured by ELISA, mRNA levels of adiponectin and PPARγ were determined by RT-PCR, and protein expressions of PPARγ, p38 MAPK and phospho-p38 MAPK were determined by Western blot. In vivo, ethanol decreased the mRNA of adiponectin in VAT and serum adiponectin significantly. Decreased PPARγ and increased activation of p38 MAPK were observed in ethanol treated group. In vitro, SB203580 increased the adiponectin and PPARγ levels in normal DMEM cultured VAT and ameliorated ethanol-induced decrease of adiponectin and PPARγ expressions. GW9662 also decreased the adiponectin levels; Both ethanol and GW9662 weakened the rosiglitazone-induced elevation of adiponectin levels in cultured VAT. These data suggest that long term intake of 0.1% ethanol down-regulated adiponectin levels, and the regulation of PPARγ via p38 MAPK pathway plays an important role in the mechanism underneath.

Tea polyphenols alleviate high fat and high glucose-induced endothelial hyperpermeability by attenuating ROS production via NADPH oxidase pathway.

BACKGROUND: Hyperglycemia-induced endothelial hyperpermeability is crucial to cardiovascular disorders and macro-vascular complications in diabetes mellitus. The objective of this study is to investigate the effects of green tea polyphenols (GTPs) on endothelial hyperpermeability and the role of nicotinamide adenine dinucleotide phosphate (NADPH) pathway. METHODS: Male Wistar rats fed on a high fat diet (HF) were treated with GTPs (0, 0.8, 1.6, 3.2 g/L in drinking water) for 26 weeks. Bovine aortic endothelial cells (BAECs) were treated with high glucose (HG, 33 mmol/L) and GTPs (0.0, 0.4, or 4 µg/mL) for 24 hours in vitro. The endothelial permeabilities in rat aorta and monolayer BAECs were measured by Evans blue injection method and efflux of fluorescein isothiocyanate (FITC)-dextran, respectively. The reactive oxygen species (ROS) levels in rat aorta and monolayer BAECs were measured by dihydroethidium (DHE) and 2', 7'-dichloro-fluorescein diacetate (DCFH-DA) fluorescent probe, respectively. Protein levels of NADPH oxidase subunits were determined by Western-blot. RESULTS: HF diet-fed increased the endothelial permeability and ROS levels in rat aorta while HG treatments increased the endothelial permeability and ROS levels in cultured BAECs. Co-treatment with GTPs alleviated those changes both in vivo and in vitro. In in vitro studies, GTPs treatments protected against the HG-induced over-expressions of p22phox and p67phox. Diphenylene iodonium chloride (DPI), an inhibitor of NADPH oxidase, alleviated the hyperpermeability induced by HG. CONCLUSIONS: GTPs could alleviate endothelial hyperpermeabilities in HF diet-fed rat aorta and in HG treated BAECs. The decrease of ROS production resulting from down-regulation of NADPH oxidase contributed to the alleviation of endothelial hyperpermeability.

Green tea polyphenols reduced fat deposits in high fat-fed rats via erk1/2-PPARγ-adiponectin pathway.

OBJECTIVE: Hypoadiponectinemia contributes to the development of obesity and related disorders such as diabetes, hyperlipidemia, and cardiovascular diseases. In this study we investigated the effects of green tea polyphenols (GTPs) on adiponectin levels and fat deposits in high fat (HF) fed rats, the mechanism of signaling pathway was explored as well. METHODS AND RESULTS: Male Wistar rats were fed with high-fat diet. GTPs (0.8, 1.6, 3.2 g/L) were administered via drinking water. Serum adiponectin and insulin were measured by ELISA, mRNA levels of adiponectin and PPARγ in visceral adipose tissue (VAT) were determined by Real-time PCR, protein levels of PPARγ, phospho (p) - PPARγ, extracellular signal regulated kinase (erk) 1/2 and p-erk1/2 in VAT were determined by western blot. GTPs treatment attenuated the VAT accumulation, hypoadiponectinemia and the decreased mRNA level of adiponectin in VAT induced by HF. Decreased expression and increased phosphorylation of PPARγ (the master regulator of adiponectin), and increased activation of erk1/2 were observed in HF group, and these effects could be alleviated by GTPs treatment. To explore the underlying mechanism, VAT was cultured in DMEM with high glucose to mimic the hyperglycemia condition in vitro. Similar to the results of in vivo study, decreased adiponectin levels, decreased expression and increased phosphorylation of PPARγ, and elevated erk1/2 phosphorylation in cultured VAT were observed. These effects could be ameliorated by co-treatment with GTPs or PD98059 (a selective inhibitor of erk1/2). CONCLUSION: GTPs reduced fat deposit, ameliorated hypoadiponectinemia in HF-fed rats, and relieved high glucose-induced adiponectin decrease in VAT in vitro. The signaling pathway analysis indicated that PPARγ regulation mediated via erk1/2 pathway was involved.